Medical carts are among the most widespread tools used in the health care industry, and similar push carts are increasingly being used in other environments, such as factories, garages, workshops, and offices. Medical carts are designed for a variety of uses and environments, but some function, e.g., as mobile computing workstations that allow health-care professionals to access, input, and distribute patients' medical information and/or medical treatment. For example, a nurse or other medical practitioner may use a medical cart equipped with a computer and/or diagnostic equipment while making rounds between patients in a hospital or other care facility. The practitioner may use the computer, e.g., to review a patient's medication information, record vital signs and other notes, and order treatment. Medical carts may be equipped with tools for diagnosis and treatment, and/or store and dispense medication. Regardless of the carts specific purpose, however, the cart must be configured to move quickly but safely through a health-care environment.
Providing a medical cart that can easily move through such a health-care environment presents several challenges. For example, modern medical carts often include a computer, display screens, an adjustable keyboard, an independent power system, extra-capacity batteries, large height-adjustable work-surfaces, and storage for medication or equipment—weighing tens to hundreds of pounds. The mass of the cart may make it difficult to control in tight areas, such as hospital rooms. Injuries are more likely to occur if the cart is not ergonomically designed. Although various “battery-assisted” solutions for improving control and maneuverability exist, they do not fully address the problem.
In order to provide mobility in tight spaces, such carts may include, for example, four caster wheels (two in the front and two in the rear), each of which may freely swivel 360° to allow for greater mobility. While the use of caster wheels may make it easier to move a cart sideways or in a tight area, caster wheels led to other drawbacks. For example, the cart's heavy weight and the caster wheels' freedom of rotation combine to make it difficult to change the direction of the mass of the cart in motion, e.g., when turning corners and to follow a straight path or move from one side to the other while traveling down a hallway (particularly a hallway with uneven floors). Therefore, there exists a need for designs that improve control, safety, and ergonomic comfort during movement of the cart.